1. Field of the Invention
The present invention is in the field of nautical equipment, and specifically relates to a flushing valve that can be inserted into the cooling water supply conduit to permit flushing of the engine of a boat.
2. The Prior Art
A number of valves are known in the prior art for permitting the flushing of the cooling system of a boat engine; however, it is believed that none of the prior art inventions has the same structure as the present invention or is able to perform all of the functions made possible by the structure of the present invention.
The closest known prior art is believed to be U.S. Pat. No. 3,550,612 issued Dec. 29, 1970 to Maxon. Maxon shows a T-shaped device that has check valves in the intake legs and that is inserted into the conduit that carries lake water to the engine. The two intake legs are closed by check valves, but only the clean water intake is urged shut by a spring. The lake water inlet is provided with a ball check valve, but the ball is not spring-loaded against its seat. Instead, the ball has holes running through it, the purpose of which is to permit a pressurized supply of fresh water to back-flush the lake water supply conduit. It does not appear to be possible, with Maxon's valve, to draw non-pressurized cleaning water or antifreeze into the engine, because the perforated ball of the intake check valve would permit air to flow in through that valve, thereby destroying the desired suction.
In U.S. Pat. No. 4,789,367, Fulks shows a Y-shaped device that includes manually-operated valves in the intake legs. Fulks' device does not use check valves, and the need for manual operation distinguishes it from the present invention.
In U.S. Pat. No. 5,038,724, Neal, et al. teach the concept of controlling the engine temperature by controlling the rate of fluid flow through the engine. This same teaching is also found in U.S. Pat. No. 5,048,468 of Broughton, et al.
As will be seen below, the present invention has several features that in combination distinguish it from the valves of the prior art.